Chuck



Feb. 5, 1946. G. THORNHILL 2,394,118

HUcK l Filed Sept. 29, 1944 3 Sheets-Sheet 1 Feb. v5, 1946. G. THoRNHlLL CHUCK Filed Sept. 29, 1944v 3 Sheets-Sheety 2 Feb. `5, 1946. Q THORNHILL 2,394,118

CHUCK Filed sept. 29, 1944 3 sheets-sheet s- Patented F eb. 5, 1946 for,

UNITED STATES PATENT OFFICE Application September 29, 1944, Serial No. 556,424.-

In Great-Britain October 12, y1,943

6 Claims'.

v this screwed engagement and consequentlythe work-*piece becomes .tightly screwed on'- the chuck byv the pressure of thecutting or otherv tool thereon and diilculty is experienced in yunscrewing `the work-piece after` theioperation thereony and particularly so when a spanner cannot be appliedto thenworkfpiece. This invention has for its'object a chuck vwhich. providesfor a quick release of the work-piece.

According; to :the presentinvention, :the Workpieceais screwed-*against a4 thrust member .-on ther-l chuck. which is held'ir1position by amovable Y,

release member yorz members z or cams which are adapted to be` operated to, releaseV the: pressure f onzthethrust; member andnthereby'permit thel work-piecerto befreely unscrewed. Thencam or.` movable release members are conveniently lliv` otallymounted and a plurality of yfsuch members may be simultaneously operatediby: acommon.

control' member: Referring .to the drawings:

Figure; 1:: is` a; side elevation ofa chuck@` con.-

structed'v according i to `this invention. f

FigurecZisi anf endview with'theworkzholder; and vi front ring attached'y to ,the thrust member;v

removed.

Figure 3y is a sectional sidegelevationgofjthebody,- ofithefchuck.; I f Figure 41s a face. view1offtheabodyofthe chuck-.g

Figure. 51 is aeplan 1of' azcam: Y

Figure 6; is'- a 4side'elevation ofzthe: cam;v Figure 'lv is Aa `plan .View ofzthextripy lever. Figure 8 is aside elevation of a bridge piece;

Figure 9 is an;underside:;view of:thewbridge piece, and' FigureflO is a plan view-of'thet-bridgegpece. withfthe' slide covery platev removed;

According tov a lconvenient embodiment s of ,thisA invention,z the chuck-.comprises a cylindrical ,body portion I: which.. has?` a-A part: 2 detachably: fixed thereto'having an :internally :screwedzsteml Ia'. at,

thefrear'- end for attachmentrtonthe; lathe orrthe;

like.V 'I'he frontiendlofy the bodyis` adaptediitovr havethework-piece :screwed thereorn. The.; means for securing the. zwork-piece varies.- according to.

thev work-piece.k Inthe constructionxillustrated drical outerend of the body I. The thrust ring 6 has.a ring 1 detachably. Xed thereto to form an abutment against which the work-piece isy screwed. This ring 1 is interchangeable and therefore can be designedaccordingto the size or shape,` of the screwedhead 4. If the work piece is externally screw threaded, the head 4Jisinternally screw threaded and when theworkpiece is screwed on the headit kapplies'pressure tothe thrust member and if the thrust member is moved'away from the Work-piece the'pressure of the work-piece thereon is relieved. The thrust member is held in position by av plurality (in the example, four) of abutment'cams `8. These cams comprise pins9 which are pivotally mounted in radial holes I0 in the body I of the chuck` and' the-portion ofeach-pin lying above the cylindrical body has a lever arm II thereon which engages a notch I2 inn a cam control ring I3 rotatably mounted onk the-body I. The upper portion of the pint in front offthe arm II has a cam .face which isv V-shaped to `Aform two'at faces and inonefposition` one iiatface' I4 holds the thrust memberf inthe forward position'with the workf piece screwed thereagainst'. The control ring.' can be rotated by ab-ar inserted inA a' tommyhole or one camcan be rotated andthe controlringzy transmits-1 movementv .to the other, cams. 'Wheni the-1 control ring I3 isrotated the leverarms II.A are pivotedi over andthe; other. at facelilies; opposite the; thrust member and lthis Vface is set back sothatithe thrust member 6 is free to move f rearwardly and relievezgthepressure on the work-A piece, whereby" such workepiece can be freely. unscrewed fromthe-chuck. The thrustmember Iiv hasralimitedsliding movement on the body of. the' chuck by means of. apin; Itk screwed throughpthe thrust. member and engagedina slot :in:the bodyof the'chuck. The thrusty member; I lies overa shoulder I'I on the cam vpin and holds the camv inthe pivot hole. The control ring I3Igis normally'springpressed in a direction to hold the cams in the operative position and. for this purpose springs I8 are mounted in an annular groove 20 inthe body of thechuck and Y pressure to again bind the work-piece. The di` ameter of the control ring and thrust piece is 'such that the cams do not project therebeyond.`

Provisions may be made to automatically re,

lease the chuck whilst it is rotating. In one i t form, arlever V23 is attached to one 'of the cams and Ywhen such lever strikes against a stop or pawl attached to a stationary part of themamounted on the chuck body and coupling the chine, the cams will'be operated to release the thrust member. A vpawl 24 is carried'by a pin 25 pivotally mounted on the bridge piece 26 fixed to the machine and the upper end of the pini Vcarries a lever 21. A slide 28 is mounted on theA .1

bridge piece and has a bevelled shoulder which isA adapted to move against the lever 21 and pivot;

such lever to withdraw the pawl Zlioutl ofthe,

path ofthe trip lever 23. The slide is normally pressed routwardly by the spring 29 in positionv to cams together so thatthey rotate in unison.

2. A chuck for holding a work-piece having screwed yengagement therewith comprising a cylindrical chuck body, a thrust ring slidably Vand non-rotatablymounted on the chuck body, i means on the said body on'which thework-piece. is fixed by screwed engagement against the thrust Y member, Va plurality of cams-feacncomprising a pinf pivotally engaged in radial hole in the chuckbody and a head on the pin forming the if cam face on one side against which the thrust ring bears and a lever on theother side, aV cam control ring rotatably mounted on the chuckV ,body andv having slots therein for engaging the said cam levers, and spring means for holding j thefcam ring inposition with theV cams butting hold the lever 21 so that the pawl is in thevin-` i operative position '(asgshown by vfull `lines Figuresr 9 and 10) but when the slideismoved inwardly Vit moves free` of the lever 21 (as rshown by broken lines Figure vand allows the pawl to be spring heldin the operative position by the spring 30'.' The spring 29 is located in a slot 32and bears against the end of the slot and a pin 33 xedto the bridge piece. The slidev` is Yheld inv 'position'by Vthe cover plate 34 which hasa central rib bearing against the inner side of the slide and forming a slide guide. When ya tool-isV operating on the work-pieceit tends to be screwed tight against the thrust member and would require an instrument to remove it. The

bridge piece 26 is mountedconcentricwith the.

chuck s o that the lever 23 travels in the `groove Y ZBajand'the pawl 24 is mounted in the recess 2Gb 'at' the jside. of the ,grooveo-If, while the chuck is rotating, the slide 28 ispressed inwardly, the trip lever 23 is turned'by the pawl 24 and the thrust member is free to'moveinwarclly and relieve vthe gripvon the work-piece. Ifthe'workpiece has been subjected to a screw threading operation it has tobe unscrewed'by reversing the rotationV of thechuck and the bridgevpiece car- ',ris a second pawl 24a mounted 'on' la pin and having a lever 21a which is controlled iby the slide 28a. If this slide is pressed inwardly;V when therotation'of the chuck is put into reverse; the pressure of theWork-pieceon theY thrust member;

is-reli'eved leaving it free to be lunscrewed. ,The

pawls 24 and 24a are reversely arranged sothat one is used when the'chuck rotates clockwise andV theY other comes into actionpwheni the chuck rotates anti-clockwise. The slides can beheld inV on the said body, means on the said body'on whichthe work-piece is fixed by screwed en'- gagement' against the thrust-memberja plurality of cams pivotally mountedon thel body ofthe chuck and'forming' movable abutment members thrust member, a cam@ control ring rotatably against-thethrust ring and against the springl pressure of which the cam ring is rotated when the cams are moved away from the thrust membe'fi 3.`A1chuck for holding. a'fwork-piefce Yhaving screwed engagement therewith comprisingP a cy lindrical chuck body, a thrustV ring'slidably and non-rotatably mounted onV thebody, a taper'ster'n detachably iixed in a taper bore offthe chuck body and having a screwed threaded head' on which the .work-piece is fixed by screwed engagement and against the thrust member, a plurality or. cams pivotally mounted on the body ofthe chuck 'and forming movable abutment members Y-a.`,f' z,inst

' which the th'ru'stvmember bears and which are adapted to be pivoted away from thethrust mem:

, ber, a cam'control ring rotatablyl mounted on the chuck body and coupling theV cams together so J that they rotate in unison, s'pringlmeans for hold' ing the cam ring in position with the cams buttingtf.'

against the thrust ring and against` thes'pring pressure of which the camring is rotated 4whenY the cams` are moved' away 'from the thrust mern-A ber."

4.`A'chuck `for holdinga worklpiece having screwed engagement therewith comprising la 'cylindrical chuck body, a thrust ring Vsli'dably and non-rotatably mountedlon the chuck body, means on th'e'said body on which Vthe 'work-piecefis fixed by screwed engagement .therewith and againstth'e thrust member, a plurality lof cams eachcompr'ising a' pirrpivot'allyl engaged inV a vradial holein'" the chuck body and a head on the pin forming:

the'cam faceon one sideagainst whichthe thrust ring bears and a lever on the otherrsidekacam control ring rotatably mounted on'a chuck body Y and having slotsl therein'ffor. erigagin'g' thewsaid cam levers,spring means'forholdin'g thec'z'tm ring in Vposition 'withf thev camsbuttin'g :against the thrustrring and against 'thespringipressure of which the cam ring is rotated when'the'cams are moved away from the thrust memberfatripj lever mounted onone ofA the cams', Vand:'aistt'niv on a stationary part'of'the' .machine against-whichthe trip lever moves whilstthechuckisrotating Y to. move the cams awayi'from'thethrust ringrtf "5. A chuck for holding alwork-piece having againstv which the; thrust'rnember bears and? f which are adapted to bepivoted awayffronfthe screwedr engagement V'therewith .comprising aV Acy'- lindricalV 'chuck'body, athrustv ring slidablyfand non-rotatably'moutedlon the body, Vataper stem detachably xed inf the taper. borefofithe; chuck Y body' having a; screwed threaded'head on which the work-piece isrxed by screwed engagel' ment therewith and against the'thrustl member,

a plurality of cams pivotallymountedlonthe body. ofwzthe chuck and` forming?- movable abutment members against whichthethrustmember bearsand 'which' are' adapted 'to be' pivotedawaytjfrom the thrust member, a cam control ring rotatably mounted on the chuck body and coupling the cams together so that they rotate in unison, spring means for holding the cam ring in position with the cams butting against the th'rust ring and against the spring pressure of which the cam ring is rotated when the cams are moved away from the thrust member, a trip lever .mounted on one of the cams, a spring controlled pawl mounted on a stationary frame against which the trip lever moves whilst the chuck is rotating to move the cams away from the thrust member and means for holding the pawl out of the path of the trip lever.

6. A chuck for holding a work-piece having screwed engagement therewith comprising a cy.

lindrical chuck body, a th'rust ring slidably and non-rotatably mounted on the chuck body, means on the said body on which the work-piece is fixed by screwed engagement therewith and against the thrust member, a plurality of cams each comprising a pin pivotally engaged in aradial hole inthe chuck body and a head on the pin forming the cam face on one side against which the thrust ring bears and a lever on the other side, a cam control ring rotatably mounted on the chuck body and having slots therein for engaging the said cam lever, spring means for holding th'e cam ring in position with the cams butting against the thrust ring and against the spring pressure of which the cam ring is rotated when the cams are moved away from the thrust member, a double armed lever on th'e outer end of one cam, a pair of spring pressed pawls mounted on a fixed frame with the pawls arranged so that one pawl will contact with one arm to turn the lever when the chuck isrotating clockwise whilst the other pawl will contact with the other arm and turn th'e lever when the chuck is rotating anti-clockwise, a lever on the pivot pin of each pawl and a slide mounted on the said frame in respect of each lever for co-acting with the respective slide for holding the pawl in an inoperative position. GEORGE THORNHILL. 

